Have you checked the alternator charging voltage? My old 'mericun car overcharged for awhile, and I did notice the brighter headlights for a day or so before I blew a high beam.

Have you pulled apart, and rechecked each plug that you pulled apart? I've been finding little corrosion on my car connections, but, anything is possible.

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My first Mercedes Benz. 4/6/07.

1984 190E (201 024) 2.3L four.